Rear extension planning drawings in Seaham

What do rear extension planning drawings cost in Seaham?

As a guide, £1,000–£2,500 including VAT for a single-storey rear extension, or £2,000–£3,500 for a two-storey scheme. A householder planning application in England costs £548 (£575 for applications made from 8 December 2026), and a lawful development certificate for proposed work costs half the householder fee. Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.

Do you need planning permission for a rear extension in Seaham?

Planning for a rear extension in Seaham follows the English householder rules.

A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.

Councils aim to decide householder applications within 8 weeks of validation, and prior approval within 42 days.

Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.

What are homes in Seaham like to extend?

Terraces and semis are typical around Seaham. On terraces a single-storey rear extension across the back yard is usually the practical choice; semis often have room for more.

How a rear extension in Seaham comes together

1. Look round and measure

   A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.

2. Design and guide price

   Two or three layout options with a guide price for each, so you choose the design knowing what it costs.

3. Approvals

   Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.

4. Written price, then build

   Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.

Rear extension planning drawings near Seaham

Neighbouring places we cover include Ryhope (2.4 miles) and Hetton-le-Hole (4.4 miles).

• Rear extension planning drawings in Ryhope
• Rear extension planning drawings in Hetton-le-Hole
• Rear extension planning drawings in Houghton-le-Spring
• Rear extension planning drawings in Sunderland
• Rear extension planning drawings in Peterlee

Other work in Seaham:

• Single-storey rear extension
• Two-storey rear extension
• Kitchen-diner rear extension
• Side return extension
• Wraparound extension
• Glazed rear extension

All rear extensions in Seaham